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Yang ZX, Fu YW, Zhao JJ, Zhang F, Li SA, Zhao M, Wen W, Zhang L, Cheng T, Zhang JP, Zhang XB. Superior Fidelity and Distinct Editing Outcomes of SaCas9 Compared with SpCas9 in Genome Editing. GENOMICS, PROTEOMICS & BIOINFORMATICS 2023; 21:1206-1220. [PMID: 36549468 PMCID: PMC11082263 DOI: 10.1016/j.gpb.2022.12.003] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/03/2021] [Revised: 11/09/2022] [Accepted: 12/13/2022] [Indexed: 12/24/2022]
Abstract
A series of clustered regularly interspaced short palindromic repeats (CRISPR)-CRISPR associated protein 9 (Cas9) systems have been engineered for genome editing. The most widely used Cas9 is SpCas9 from Streptococcus pyogenes and SaCas9 from Staphylococcus aureus. However, a comparison of their detailed gene editing outcomes is still lacking. By characterizing the editing outcomes of 11 sites in human induced pluripotent stem cells (iPSCs) and K562 cells, we found that SaCas9 could edit the genome with greater efficiencies than SpCas9. We also compared the effects of spacer lengths of single-guide RNAs (sgRNAs; 18-21 nt for SpCas9 and 19-23 nt for SaCas9) and found that the optimal spacer lengths were 20 nt and 21 nt for SpCas9 and SaCas9, respectively. However, the optimal spacer length for a particular sgRNA was 18-21 nt for SpCas9 and 21-22 nt for SaCas9. Furthermore, SpCas9 exhibited a more substantial bias than SaCas9 for nonhomologous end-joining (NHEJ) +1 insertion at the fourth nucleotide upstream of the protospacer adjacent motif (PAM), indicating a characteristic of a staggered cut. Accordingly, editing with SaCas9 led to higher efficiencies of NHEJ-mediated double-stranded oligodeoxynucleotide (dsODN) insertion or homology-directed repair (HDR)-mediated adeno-associated virus serotype 6 (AAV6) donor knock-in. Finally, GUIDE-seq analysis revealed that SaCas9 exhibited significantly reduced off-target effects compared with SpCas9. Our work indicates the superior performance of SaCas9 to SpCas9 in transgene integration-based therapeutic gene editing and the necessity to identify the optimal spacer length to achieve desired editing results.
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Affiliation(s)
- Zhi-Xue Yang
- State Key Laboratory of Experimental Hematology, National Clinical Research Center for Blood Diseases, Haihe Laboratory of Cell Ecosystem, Institute of Hematology & Blood Diseases Hospital, Chinese Academy of Medical Sciences & Peking Union Medical College, Tianjin 300020, China
| | - Ya-Wen Fu
- State Key Laboratory of Experimental Hematology, National Clinical Research Center for Blood Diseases, Haihe Laboratory of Cell Ecosystem, Institute of Hematology & Blood Diseases Hospital, Chinese Academy of Medical Sciences & Peking Union Medical College, Tianjin 300020, China
| | - Juan-Juan Zhao
- State Key Laboratory of Experimental Hematology, National Clinical Research Center for Blood Diseases, Haihe Laboratory of Cell Ecosystem, Institute of Hematology & Blood Diseases Hospital, Chinese Academy of Medical Sciences & Peking Union Medical College, Tianjin 300020, China
| | - Feng Zhang
- State Key Laboratory of Experimental Hematology, National Clinical Research Center for Blood Diseases, Haihe Laboratory of Cell Ecosystem, Institute of Hematology & Blood Diseases Hospital, Chinese Academy of Medical Sciences & Peking Union Medical College, Tianjin 300020, China
| | - Si-Ang Li
- State Key Laboratory of Experimental Hematology, National Clinical Research Center for Blood Diseases, Haihe Laboratory of Cell Ecosystem, Institute of Hematology & Blood Diseases Hospital, Chinese Academy of Medical Sciences & Peking Union Medical College, Tianjin 300020, China
| | - Mei Zhao
- State Key Laboratory of Experimental Hematology, National Clinical Research Center for Blood Diseases, Haihe Laboratory of Cell Ecosystem, Institute of Hematology & Blood Diseases Hospital, Chinese Academy of Medical Sciences & Peking Union Medical College, Tianjin 300020, China
| | - Wei Wen
- State Key Laboratory of Experimental Hematology, National Clinical Research Center for Blood Diseases, Haihe Laboratory of Cell Ecosystem, Institute of Hematology & Blood Diseases Hospital, Chinese Academy of Medical Sciences & Peking Union Medical College, Tianjin 300020, China
| | - Lei Zhang
- State Key Laboratory of Experimental Hematology, National Clinical Research Center for Blood Diseases, Haihe Laboratory of Cell Ecosystem, Institute of Hematology & Blood Diseases Hospital, Chinese Academy of Medical Sciences & Peking Union Medical College, Tianjin 300020, China
| | - Tao Cheng
- State Key Laboratory of Experimental Hematology, National Clinical Research Center for Blood Diseases, Haihe Laboratory of Cell Ecosystem, Institute of Hematology & Blood Diseases Hospital, Chinese Academy of Medical Sciences & Peking Union Medical College, Tianjin 300020, China; Center for Stem Cell Medicine, Chinese Academy of Medical Sciences, Tianjin 300020, China; Department of Stem Cell & Regenerative Medicine, Peking Union Medical College, Tianjin 300020, China
| | - Jian-Ping Zhang
- State Key Laboratory of Experimental Hematology, National Clinical Research Center for Blood Diseases, Haihe Laboratory of Cell Ecosystem, Institute of Hematology & Blood Diseases Hospital, Chinese Academy of Medical Sciences & Peking Union Medical College, Tianjin 300020, China.
| | - Xiao-Bing Zhang
- State Key Laboratory of Experimental Hematology, National Clinical Research Center for Blood Diseases, Haihe Laboratory of Cell Ecosystem, Institute of Hematology & Blood Diseases Hospital, Chinese Academy of Medical Sciences & Peking Union Medical College, Tianjin 300020, China.
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Wei N, Shang L, Liu J, Wang M, Liu Y, Zhu C, Fei C, Zhang L, Yang F, Gu F. Engineered Staphylococcus auricularis Cas9 with high-fidelity. FASEB J 2023; 37:e23060. [PMID: 37389931 DOI: 10.1096/fj.202202132rr] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2022] [Revised: 06/03/2023] [Accepted: 06/13/2023] [Indexed: 07/01/2023]
Abstract
CRISPR-Cas9 is a versatile gene editing tool with a broad application of basic research and clinical therapeutics. However, the potential impact caused by off-target effects remains a critical bottleneck. The small Cas9 ortholog from Staphylococcus auricularis (SauriCas9) was identified, which recognizes a 5'-NNGG-3' protospacer adjacent motif (PAM), exhibiting high activity for genome editing. Recently, we also reported enhanced-fidelity Staphylococcus aureus Cas9 (efSaCas9), which harbors a single mutation N260D. Protein sequence alignment revealed that SauriCas9 has 62.4% sequence identity with SaCas9. Because SauriCas9 is more flexible in recognizing the target sequence with PAM of 5'-NNGG-3' than SaCas9 of 5'-NNGRRT-3' PAM, we sought to test whether key mutation(N260D) or adjacent residue mutation in efSaCas9 can be appliable to SauriCas9. With this concept, two engineered SauriCas9 variants (SauriCas9-HF1, harboring the N269D mutation; SauriCas9-HF2, harboring the D270N mutation) dramatically improved targeting specificity by targeted deep sequencing and GUIDE-seq. At certain sites, reduced off-target effects (approximately 61.6- and 111.9-fold improvements) of SauriCas9-HF2 compared with wild-type SauriCas9 were observed. Overall, two identified SauriCas9 variants (SauriCas9-HF1 and SauriCas9-HF2) expand the utility of the CRISPR toolkit for research and therapeutic applications.
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Affiliation(s)
- Nan Wei
- Shanghai Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Shanghai, China
- Key Laboratory of Veterinary Chemical Drugs and Pharmaceutics, Ministry of Agriculture and Rural Affairs, Shanghai, China
| | - Lu Shang
- Shanghai Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Shanghai, China
- Key Laboratory of Veterinary Chemical Drugs and Pharmaceutics, Ministry of Agriculture and Rural Affairs, Shanghai, China
| | - Jing Liu
- Shanghai Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Shanghai, China
- Key Laboratory of Veterinary Chemical Drugs and Pharmaceutics, Ministry of Agriculture and Rural Affairs, Shanghai, China
| | - Mi Wang
- Shanghai Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Shanghai, China
- Key Laboratory of Veterinary Chemical Drugs and Pharmaceutics, Ministry of Agriculture and Rural Affairs, Shanghai, China
| | - Yingchun Liu
- Shanghai Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Shanghai, China
- Key Laboratory of Veterinary Chemical Drugs and Pharmaceutics, Ministry of Agriculture and Rural Affairs, Shanghai, China
| | - Chuangang Zhu
- Shanghai Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Shanghai, China
| | - Chenzhong Fei
- Shanghai Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Shanghai, China
- Key Laboratory of Veterinary Chemical Drugs and Pharmaceutics, Ministry of Agriculture and Rural Affairs, Shanghai, China
| | - Lifang Zhang
- Shanghai Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Shanghai, China
- Key Laboratory of Veterinary Chemical Drugs and Pharmaceutics, Ministry of Agriculture and Rural Affairs, Shanghai, China
| | - Fayu Yang
- Shanghai Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Shanghai, China
- Key Laboratory of Veterinary Chemical Drugs and Pharmaceutics, Ministry of Agriculture and Rural Affairs, Shanghai, China
| | - Feng Gu
- Shanghai Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Shanghai, China
- Key Laboratory of Veterinary Chemical Drugs and Pharmaceutics, Ministry of Agriculture and Rural Affairs, Shanghai, China
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Full-Length Model of SaCas9-sgRNA-DNA Complex in Cleavage State. Int J Mol Sci 2023; 24:ijms24021204. [PMID: 36674715 PMCID: PMC9867433 DOI: 10.3390/ijms24021204] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2022] [Revised: 12/24/2022] [Accepted: 12/27/2022] [Indexed: 01/10/2023] Open
Abstract
Staphylococcus aureus Cas9 (SaCas9) is a widely used genome editing tool. Understanding its molecular mechanisms of DNA cleavage could effectively guide the engineering optimization of this system. Here, we determined the first cryo-electron microscopy structure of the SaCas9-sgRNA-DNA ternary complex. This structure reveals that the HNH nuclease domain is tightly bound to the cleavage site of the target DNA strand, and is in close contact with the WED and REC domains. Moreover, it captures the complete structure of the sgRNA, including the previously unresolved stem-loop 2. Based on this structure, we build a full-length model for the ternary complex in cleavage state. This model enables identification of the residues for the interactions between the HNH domain and the WED and REC domains. Moreover, we found that the stem-loop 2 of the sgRNA tightly binds to the PI and RuvC domains and may also regulate the position shift of the RuvC domain. Further mutagenesis and molecular dynamics simulations supported the idea that the interactions of the HNH domain with the WED and REC domains play an important role in the DNA cleavage. Thus, this study provides new mechanistic insights into the DNA cleavage of SaCas9 and is also useful for guiding the future engineering of SaCas9-mediated gene editing systems.
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Huang X, Yang D, Zhang J, Xu J, Chen YE. Recent Advances in Improving Gene-Editing Specificity through CRISPR-Cas9 Nuclease Engineering. Cells 2022; 11:2186. [PMID: 35883629 PMCID: PMC9319960 DOI: 10.3390/cells11142186] [Citation(s) in RCA: 19] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2022] [Revised: 07/06/2022] [Accepted: 07/11/2022] [Indexed: 11/25/2022] Open
Abstract
CRISPR-Cas9 is the state-of-the-art programmable genome-editing tool widely used in many areas. For safe therapeutic applications in clinical medicine, its off-target effect must be dramatically minimized. In recent years, extensive studies have been conducted to improve the gene-editing specificity of the most popular CRISPR-Cas9 nucleases using different strategies. In this review, we summarize and discuss these strategies and achievements, with a major focus on improving the gene-editing specificity through Cas9 protein engineering.
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Affiliation(s)
- Xiaoqiang Huang
- Center for Advanced Models for Translational Sciences and Therapeutics, University of Michigan Medical Center, Ann Arbor, MI 48109, USA; (D.Y.); (J.Z.); (J.X.)
| | | | | | | | - Y. Eugene Chen
- Center for Advanced Models for Translational Sciences and Therapeutics, University of Michigan Medical Center, Ann Arbor, MI 48109, USA; (D.Y.); (J.Z.); (J.X.)
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